Nelken has distinguished himself in several different areas of scholarship and has been an indefatigable promoter of comparative research and of systematic empirical research in scholarly communities where it is underdeveloped. Perhaps his greatest contribution has been to champion the systematic study of legal culture. He has published a number of important methodological articles and books explaining how this elusive concept can be put to good use in sociolegal studies, and to especially good use in comparative research. Some of his most important books in this area includeThe Politics of Corruption and the Corruption of Politics (1996), Comparing Legal Cultures (1997), Contrasting Criminal Justice (2000), Adapting Leal Cultures (2001, with J. Feest), Exploring Legal Cultures (2007, with F Burisma), A Handbook of Comparative law (with E. Orucu), European Ways of Law (with V. Gessner), and Comparative Criminal Justice (2010).